Reversible internal gear pump



5 Sheets-Sheet l G m L T N E w H w Filed April 10, 1946 INVENTOR.

W/LL/AM H WENTL/IVG G W L T N E w H w REVERSIBLE INTERNAL GEAR PUMP 5 Sheets-Sheet 2 Filed April 10, 1946 INVENTOR. W/L .4 MN 14 51/74 //VG BY M Q O Dec, 3949 w. H. WENTLING REVERSIBLE INTERNAL GEAR PUMP 5 Sheets-Sheet 3 Filed April 10, 1946 INVENTOR.

m n m y W H M M L M W mam? W. H. WENTL ING REVERSIBLE INTERNAL GEAR PUMP 5 Sheets-Sheet 4 Filed April 10, 1946 G R w W T r W 2 1 l M w l m; r r a H A 5 m I M F W Dec. 6, 1949 w. H. WENTLING 2,490,391

REVERSIBLE INTERNAL GEAR PUMP Filed April 10, 1946 5 Sheets-Sheet 5 INVEN TOR. W LL/AM WENTL/NG Y y/lmua. 8 M

Patented Dec. 6, 1949 2,490,391 REVERSIBLE INTERNAL GEAR PUMP William H. Wentling, Harrison Township, Montgomery County. Ohio, assignor to Chrysler Corporation, Highland Park, Mich, a corporation' of Delaware ApplicationApril 10, 1946, Serial No. 660,981

14 Claims. 1 7

My present invention relates to pumps of general utility in many fields and of particular utility for circulating a lubricating medium through engines or machines of any type which may operate in reverse. A particular machine of this type is a refrigerant compressor such as disclosed and claimed in the patent to Neeson, No. 2,185,473 of January 2, 1940, or Neeson, No. 2,225,228 of December 7, 1940, each of which comprises a compressing unit for refrigerants including a motor and a plurality of compressing cylinders, the cylinders being sealed into a casing a portion of which forms an enclosed oil reservoir. Within this oil reservoir there is mounted a pump for circulating oil to lubricate the bearings, pistons and other parts, and in the case of the latter patent to cool the motor. As fully set forth in the latter patent the motors of such units may operate in either direction, the direction of rotation depending entirely upon the manner in which the motor connections are made to the power lines. Through carelessness or error, the connections may be made so that the motor operates counterclockwise whereas clockwise rotation would be desired, or even after the original connections have been made correctly the lines may be reversed somewhere between the power plant and the motor with the same effect. The compressing cylinders of the foregoing patents and of almost all like mechanisms are capable of operating regardless of the direction of rota- -tion of the motor to which they are connected, and as set forth in the latter patent it is desirable to have a pump having automatic reversin features so that the pump will always force lubricant through the system in the proper direction. As set forth and claimed in the latter patent a form of pump such as disclosed in the patent to Wilsey, No. 1,700,818 of February 5, 1929, may be utilized, such a pump comprising an external toothed driving e1ement,- an internal toothed rotor of a lesser number of teeth and a floating member including a crescent which may reverse its position through 180 degrees upon reversal of direction of the driving member through frictional engagement therewith. 'As set forth and claimed in the patent to Neeson 2,151,482 of March 21, 1939, a simpler construction comprising the type of pump including an internal, toothed driving member and an external, toothed rotor having one more tooth than the driver may be used in combination with a floating reversing member which must rotate through an arc of 130 degrees upon reversal of rotation, An object of the present invention is to devise a simple form of pump eliminating most of the machining required, eliminating most of the possible causes of excess friction tending to prevent movement of the reversing member and otherwise simplifying the construction.

A further object of the present invention is to devise a pump which will operate upon reverse movement of the driving member through the minimum are possible, for example, an arc in the range of 20 to 40 degrees. In the present disclosure I have devised a pump which will operate after a reversal of 33 degrees, but it is to be appreciated that reduction of this figure is possible depending upon the extent of the pump gear teeth. The present example arrives at the figure of 33 degrees with the use of a pump having 8 teeth on the driving member and 9 teeth on the outer rotor. The teeth of the driving member thus subtend arcs of 45 degrees and on the driven member the teeth subtend arcs of 40 degrees, the movement required for reversal being less than the width of either type of tooth. If a greater number of teeth were employed on the pump members the movement of reversal could be lessened still farther. Even with the present example the movement of 33 degrees could be lessened through closer tolerances than necessary for the purposes of the invention. It is thus seen that the pump of my invention will commence operating upon the minimum movement of the driving member in either direction, and immediate reaction of the pump is thus assured. A further advantage is that due to the minimum movement required a possible source of failure to reverse is reduced to a minimum.

It is to be noted in Patent No. 2,225,228 that engagement of the driven member of the pump with the crank shaft of the compressor is accomplished through a crossbar-crankpin driving connection so that reversal of the motor first permits the crankpin to swing through an arc of substantially 180 degrees before the opposite end of the crossbar is engaged, thereafter movement of the driven member is required through at least 180 degrees before pumping action can commence.

. Even in the case of the Patent No. 2,185,473

stantially 180 degrees plus 33 degrees of movement. If a pin and slot connection were used the pump could operate after movement of substantially 33 degrees only. I have thus reduced the reversing time to an absolute minimum which may be of advantage in some cases, particularly in the case of compressing unitsof the type disclosed in Patent 2,185,473 or in the patent to Neeson No. 2,369,841 of February 20, 1945, in either of which the lubricating medium is used to operate cylinder unloading means. I thereby am able to achieve practically instantaneous control of the compressor unloading means after a reversal of rotation.

The foregoing and other objects and advantages of the present invention will be more fully apparent from a study of the following specification taken in connection with the accompanying drawings wherein like numerals refer to like parts throughout.

In the drawings Fig. 1 discloses a pump of the present invention mounted in a compressing unit; Fig. 2 is a plan view of the end bell of the compressing unit looking along the line 2-2 of Fig. 1 in the direction of the arrows; Fig. 3 is a vertical section taken along line 3--3 of Fig. 2; Fig. 4 is a plan view on an enlarged scale of the top of the pump casing which together with a portion of the end bell forms a complete casing for the operating parts of the pump; Fig. 5 is a vertical section taken along line 55, of Fig. 4; Fig. 6 is a plan view of the floating reversing member; Fig. 7 is a side elevation of the floating reversing member; Fig. 8 is a plan view of one type of toothed driving gear; Fig. 9 is a plan view of the driving gear associated with the rotor gear; Fig. 10 is a schematic representation of the pump parts (disclosing a modified form of gear tooth) in the positions they assume upon rotation in one direction; and Fig. 11 is a similar view showing the parts in the positions they assume upon rotation in the opposite direction.

The pump is shown in Fig. 1 as associated with a compressor of the hermetically sealed type comprising a substantially cylindrical casing having portions forming a journal to mount a crankshaft 2i having an eccentric crankpin 22 to which are connected a plurality of piston rods 23 each carrying a piston 24. Each piston reciprocates within a cylinder sleeve 25 extending through a suction manifold 26, and discharges gas into a discharge space 21 in a cylinder head 28, the cylinder headsbeing connected to a discharge manifold 29. Entrance of the gas to the interior of the cylinder is accomplished through V a ring valve 30, possibly supplemented by auxiliary ports 3|, and discharge i accomplished through a disc valve 32 permitting discharge to the space 21. Other types of piston and valve assemblies, and other types of compressing machines, or other machines or engines may be lubricated by the present invention.

The end of the 'crankpin 22 is provided with an extension 35 adapted to engage a crossbar 36 carried by a vertical stub shaft 31 journaled in the pump casing member 38. The pin 35 will thus rotate the stub shaft 31 and may drive the stub shaft in either direction. The stub shaft, extends into the upper portion of a cylindrical cavity 40 having its side walls within the member 38, and one end of which is formed by the upper face of the end bell ll of the compressor casing. An externally toothed pump gear 42 is attached to the end of stub shaft 31 to be rotated thereby and the teeth of the pump gear mesh with an internally toothed rotor gear 43 snugly fitting within the end of the cavity 30. The gear members are of the same thickness and are smoothly finished on both end faces so as to fill the end of the cavity except for the spaces between the teeth as shown in Fig. 9. From an inspection of Fig. 9 it will be seen that the stub shaft 31 is mounted eccentrically with respect to the cavity 40 and the rotor 43 by a distance substantially equal to one half of the gear tooth depth, and that the rotor has one .more tooth than the driver, so that progressively increasing spaces occur between the members on one side of a diameter and, continuing circumferentially in the same direction, progressively decreasing spaces occur on the opposite side of the diameter. Thus if the members are submerged in a liquid the liquid will be drawn into the spaces at one side and forced therefrom at the other side of a diameter. The form of gear tooth shown in Figs. 8 and 9 is one form the gear teeth may assume, but other forms of pump gears may be substituted therefor, such as the form illustrated in the patent to Hill 1,486,836 of March 11, 1924, the gear tooth shapes of which are illustrated in Figs. 10 and 11. In any case I prefer the type of gear pump in which there are one less tooth on the driven member than there are on the rotor member so that the simplest form of construction may be realized. It is likewise to be appreciated that the outer gear member may be the driver and the inner gear member may be the driven member, without affecting the operation of the device or departing from my invention.

The remaining space of the cavity 40 not occupied by the gear members is occupied by a floating reversing disk 50 snugly fitting therein. The reversing member is smoothly finished on all surfaces, and the upper face of the end bell 4| and the side walls of the cavity 40 are smoothly finished, so that the friction engagement of the gear members with the adjacent face of the reversing member will cause the reversing member to assume one or the other extreme positions dependin upon the direction of rotation. The reversing member is provided with a pair of grooves 5| and 52, each lying wholly upon one side of a diameter. Each groove commences at an inwardly spaced point and extends arcuately at such a radius as to be adjacent some of the teeth of the gears and then extends tangentially to the edge of the disk. The grooves may comprise slots extending entirely through the disk but it is preferable to have them extend only partially through the disk for rigidity, and to lessen the frictional engagement of the adjacent faces of the disk and the bell. The groove 5| underlies the pockets between the gear teeth at the left of the diameter and the groove .52 underlies the pockets at the right of the diameter. The arcuate distance between the inner end of one groove and outer end of the other groove may be substantially less than the minimum 33 degrees without affecting the operation, and in fact may be preferable for completing suction and discharge. The outer edge of the disk is provided with a recess having end surfaces 53 and 54 spaced slightly more than 33 degrees apart, and the side wall of the cavity 40 is provided with an inwardly extending pin 55 adapted to extend into the recess and engage with one or the other of the abutments formed by the recess end surfaces. As clearly seen in Figs. 10 and 11, when the pin 55 engages either 3 abutment 53 or 54. the grooves 5| and 52 will nevertheless underlie the same pockets between the gear teeth,

The casing member 38 is provided with a suction passageway 68 extending throughout the greater portion of the left side of the member and a discharge passageway 6| extending throughout the greater portion of the right side of the member. The suction passageway has two openings 52 and 63 communicating with the cavity 4|! at a few degrees arcuate distance from the diameter dividing the suction and discharge sides and the discharge passageway 6| has two openings 64 and 65 communicating with the cavity at a few degrees from the diameter. This diameter is the same diameter along which the shaft 31 is placed eccentric to the cavity. The centers of adjacent suction and discharge openings 62 and 68, and 63 and 65, are preferably substantially 33 degrees apart. The suction openings 62 and 63 are thus separated by a large land 66, and the discharge openings 64 and 65 are separated by a large land 61, the lands 66 and 61 being substantially equal and occupying most of the side wall of the cavity. Adjacent suction and discharge openings 62 and 64 are separated by a narrow land 68 and adjacent suction and discharge openings 63 and 65 are separated by a similar narrow land 69 of substantially equal length.

Since the two large lands are equal and the two small lands are equal in extent, the suction openings will be diametrically opposite to the discharge openings, thus openings 62 and 65 lie along one diameter and openings 63 and 64 lie along another'diameter at an angle of substantially 33 degrees, each of which forms an angle of substantially 16 degrees with the diameter of gear eccentricity. When the pin 55 engages abutment 53 groove 5| will communicate with opening 62, and

4 at the same time groove 52 will communicate with opening 65. Upon reversal of rotation the frietional drag of the gears and of the liquid engaged in the pockets will cause the floating reversing disk to snap through an are limited by the engagement of pin with abutment 54. This places groove 5| in communication opening 64, and groove 52 in communication with opening 63. Thus upon clockwise rotation of the gears groove 5| communicates with the suction passageway and 52 with the discharge passageway, and upon counter-clockwise rotation of the gears the grooves reverse their functions since groove 5| communicates with the discharge passageway and groove 52 communicates with the suction passageway.

. As seen in Figs. 1 to 4 inclusive the end bell 4| is provided with a vertically drilled hole 18 in position to communicate with the passageway in the member 88. An outwardly extending horizontal hole 1| joins 10 and its outer end is closed by a plug T2. A second vertically extending hole 13 extends from II to the upper face of the end bell adjacent a relatively thin walled portion 14 of the main casing 28, the holes 10, "II and 13 thus providing a suction passage communicating with suction passageway 60 and the interior of the casing to conduct oil from the bottom of the casing to the pump. When the compressor of Fig. 1 is mounted in the position illustrated with the motor vertically over the cylinders and pump, the oil flowing from the sump portions of the end bell will flow vertically through opening 13 upon operation of the pump. The mechanism may 0perate with the crankshaft 2| in a horizontal posi- 6 tion by so placing the unit as to have opening 13 at the bottom of the unit in which case oil will flow horizontally through hole 18 and vertically upward through hole ll into the pump. It

makes no difference to the pump unit or the compressor which position is selected, and by connecting tubing in place of the plug 12 the motor may be placed vertically beneath the compressing cylinders and the pump without affecting operation of either. I

The end bell ll is also provided with a vertically extending hole 15 joined by a horizontally drilled hole 16 having its end closed by a plug l1 and communicating with a hole 18 extending upward to join a hole 19 in a relatively thickwalled portion of the main casting 20 thus providing a pressure lubrication passage. As more fully illustrated in the aforementioned Patent No. 2,225,228 hole 19 may communicate with hole 8| extending to the main bearings and having further connection to the crank pin 22 for lubricating the piston rods. A branch of hole 8| may lead to means to cool the motor windings and a further branch 82 may lead to a spring-loaded pressure relief valve 83 adapted to open a relief opening 84 when excessive pressure is developed. Details of the lubricating system are not essential to an understanding of the present invention.

A feature of the present invention comprises means to insure maximum frictional engagement of the reversing disk 50 with the gear members, and minimum frictional engagement of the reversing disk with the cavity walls. As seen in Figs. 2 and 3 hole 16 has an extension 85 terminating beneath-the vertical center of the cavity 40 and is joined by a vertically extending opening 0 ing 86 and is upwardly urged by a spring 88 mounted within the lower portion of the opening 86. The ball 81 thus provides a ball thrust bearing for the disk 58 to assure free movement of the disk when the pump is not operating. When the pump is operating the force of the discharge in groove 52 will so far exceed the force of the suction in groove 5| that the disk might tend to bind were it not for the application of discharge pressure to the lower surface of the disk through passages 15, 85 and 86 acting against the ball 87. Even if oil leaks past the ball 81 the snug fit of the side walls of the disk and the cavity tend to prevent escape of oil from beneath the lower surface of the disk and whether leakage occurs or not the disk will be forcibly engaged with the faces of the gear members to cause it to assume the position indicated by the direction of rotation. 4

In Fig. 10 the pump of the Hill patent, which for my purpose is identical with the pump illustrated in Fig. 9, is shown with the parts in the positions assumed for clockwise rotation, with the direction of oil flow indicated. Fig. 11 shows the parts in the positions assumed for counterengagement is desired. It will also be apparent that I have devised a reversing mechanism-having the minimum number of parts, that all parts are simple to make, and that the number and 75 shape of the pump gear teeth are immaterial. thu

clockwise rotation, with the direction of flow indiassuring supply from various gear or gear pump manufacturers. There is a minimum of noise and vibration possible with my invention which is of great importance in certain applications, such as air conditioning or refrigeration compressors to be installed in dwelling or omce spaces. There is also a minimum possibility for dirt or other foreign material to cause failure of the Pump to reverse since any such material would probably be confined to the passageways or to the meeting faces of the gear members and reversing disk where friction is desired anyway, at least to an extent sufficient to cause reversal of movement. If any such foreign matter should become lodged, it would probably be dislodged upon initial reversal of movement and would flow on to be screened out by the usual oil filter or the like.

Having illustrated and described the preferred form of my invention I now claim as my invention the following. All such modifications in detail and arrangement as come within the scope of the following claims are considered a part of my invention.

I claim:

1. A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavity at the other side of said diameter, the arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internally toothed rotor gear snugly fitting one end of said cavity and freely rotatable therein, an externally toothed inner gear meshing with said rotor gear, said inner gear having a lesser number of teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side of a diameter and compression at the other, a cylindrical reversing disk element snugly filling the remainder of said cavity and having one end face frictionally engaging the exposed faces of said gears, said end face having two grooves therein, each commencing at an internal point,

extending arcuately at such a radius as to be adjacent-some of the teeth of the gears, and then extending to the side of the disk, each of said grooves lying wholly at one side of a diameter and the ends of said grooves being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said disk element is so positioned as to have one groove in communication with one of said suction openings and the other in communication with one of said discharge openings, a stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, and a second stop on one of said elements engageable by means on the other of said elements for limiting rotation of said disk element to substantially the are between adjacent suction and discharge openings, whereby said grooves may switch functions when said disk element is frictionally rotated from one position to the other depending on the direction of rotation of said gears but said passageways will nevertheless function in the same manner.

2. A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavity at the other side of said diameter, the arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internally toothed rotor gear snugly fitting one end of said cavity and freely rotatable therein, an externally toothed inner gear meshing with said rotor gear, said inner gear having a lesser number of teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side of a diameter and compression at the other, a cylindrical reversing disk element snugly filling the remainder of said cavity and having one end face frictionally engaging the exposed faces of said gears, said disk element having two passageways formed therein, each commencing at an internal point, extending arcuately at such a radius as to be adjacent some of the teeth of the gears, and then extending to the side of the disk, each of said passageways lying wholly at one side of a diameter and the ends of said passageways being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said disk element is so positioned as to have one passageway in communication with one of said suction openings and the other in communication with one of said discharge openings, a stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, and a second stop on one of said elements engageable by means on the other of said elements for limiting rotation of said disk element to substantially the arc between adjacent suction and discharge openings, whereby said disc passageways may switch functions when said disk element is frictionally rotated from one position to the other depending on the direction of rotation of said casing gears but said passageways will nevertheless function in the same manner.

3. A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavity at the other side of said diameter, the arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands betweenadjacent suction and discharge openings being substantially of equal each commencing at an internal point, extending arcuately at such a radius as to be adjacent some of the teeth of the gears, and then extending to the side of the disk element, each of said grooves lying wholly at one side of a diameter and the ends of said grooves being diametrically opposed whereby one acts as a continuation of said S1101 tion passageway and the other acts as a continuation of said discharge passageway when said disk element is so positioned as to have one groove in communication with one of said suction openlugs and the other in communication with one of said discharge openings, a stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, and a second stop on one of said elements engageable by means on the other of said elements for limiting rotation of said disk to substantially the are between adjacent suction and discharge openings, whereby said grooves may switch functions when said disk element is frictionally rotated from one position to the other depending on the direction of rotation of said gears but said passageways will nevertheless function in the same manner, the angle between the center of adjacent suction and discharge openings being less than the angle between teeth of either of said gears whereby said disk element may be limited to a minimum movement by said stops.

4. A reversible pump comprising a casing element having a cylindrical ca'vity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavity at the other side of said diameter, thearcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internally toothed rotor gear snugly fitting one end of said cavity and freely rotatable therein, an externally toothed inner gear meshing with said rotor gear, said inner gear 'tions when said disk element is frictionally r0- tated from one position to the other depending on the direction of rotation of said gears but said passageways will nevertheless function in thesame manner, the angle between adjacent suction and discharge openings being less than the angle' between teeth of either of said gears whereby said disk element may be limited to a minimum movement by said stops.

5. A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavityat the other side of said diameter, the arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internally toothed rotor gear having a lesser number of teeth than said rotor each commencing at an internal point, extending arcuately at such a radius as to be adjacent some of the teethof the gears, and then extending to the side of the disk element, each of said ports lying wholly at one side of a diameter and the ends of said ports being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said disk element is so positioned as to have one port in communication with one of said suction openings and the other in communication with one of said discharge openings, a stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, and a second stop on one of said elements engageable by means on the other of said-elements for limiting rotation of said disk element to substantially the are between adjacent suction and discharge openings, whereby said ports may swi ch func- 75 snugly fitting one end of said cavity and freely.

snugly fitting one end of said cavity and freely rotatable therein. a driven, externally toothed inner gear meshing with said rotor gear, said inner gear having one less teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side of a diameter and compression at the other, a cylindrical reversing disk element snugly filling the remainder of said cavity and having one end face frictionally engaging the exposed faces of said gears said end face having two grooves therein, each commencing at an internal point, extending arcuately at such a radius as to be adjacent some of the teeth of the gears, and then extending to the side of the disk element, each ofsaid grooves lying wholly at one side of a diameter and the ends of said grooves being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said disk element is so positioned as to have one groove in communication with one of said suction openings and the other in communication with one of said discharge openings, a stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, and a second stop on one of said elements engageable by means on the other of said elements for limiting rotation of said disk element to substantially the are between adjacent suction and discharge openings, whereby said grooves may switch functions when said disk element is frictionally rotated from one position to the other depending on the direction of rotation of said gears but said passageways will nevertheless function in the same manner, the angle defined bysaid stops being such as to limit movement of said disk element to approximately thirty-three degrees.

6. A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavity at the other side of said diameter, the arcuate land between said suction openingsbeing of substantially the same length as the arcuate land between said discharge openings and the arcuate landsbetween adjacent suction and discharge openings being substantially of equal length; a cylindrical, internally toothed rotor gear 11 rotatable therein, a driven, externally toothed inner gear meshin with said rotor gear, said inner gear having one less teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side of a diameter and compression at the other, a cylindrical reversing disk element snugly filling the remainder of said cavity and having one end face frictionally engaging the exposed faces of said gear, said disk element having two ports therein, each commencing at an internal point, extending arcuately at such a radius as to be adjacent some of the teeth of the gears, and then extending to the side of the disk element, each of said ports lying wholly at one side of a diameter and the ends of said ports being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said disk element is so positioned as to have one port in communication with one of said suction openings and the other in communication with one of said discharge openings, a stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, and a second stop on one of said elements engageable by means on the other of said elements for limiting rotation of said disk element to substantially the arc between adjacent suction and discharge openings, whereby said ports may switch functions when said disk element is frictionally rotated from one position to the other depending on the direction of rotation of said gears but said passageways will nevertheless function in the same manner, the angle defined by said stops being such as to limit movement of said disk element to approximately thirty-three degrees.

7. .A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavity at the other side of said diameter, the arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internally toothed rotor gear snugly fitting one end of said cavity and freely rotatable therein, an externally toothed inner gear meshing with said rotor gear, said inner gear having a lesser number of teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side of a diameter and compression at the other, a cylindrical reversing disk element snugly filling the remainder of said cavity and having one end face frictionally engaging the exposed faces of said gears, said end face having two grooves therein, each commencing at an internal point, extending arcuately at such a radius as to be adjacent some of the teeth of the gears, and then extending to the side of the disk element, each of said grooves lying wholly at one side of a diameter and the ends of said grooves being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said disk element is so positioned as to have one groove in communication with one of said suction openings and the other in communication with one of said discharge openings, a stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, a second stop on one of said elements engageable by means on the other of said elements for limiting rotation of said disk element to substantially the arc between adjacent suction and discharge openings, whereby said grooves may switch functions when said disk element is frictionally rotated from one position to the other depending on the direction of rotation of said gears but said passageways will nevertheless function in the same manner, and thrust bearing means in said casing element acting upon the other end face of said disk element.

8. A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavity at the other side of said diameter, the arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internally toothed rotor gear snugly fitting one end of said cavity and freely rotatable therein, a driven externally toothed inner gear meshing with said rotor gear, said inner gear having onelless teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side of a diameter and compression at the other, a cylindrical reversing disk element snugly filling the remainder of said cavity and having one end face frictionally engaging the exposed faces of said gear, said end face having two channels therein, each commencing at an internal point, extending arcuately at such a radius as to be adjacent some of the teeth of the gears, and then extending to the side of the disk element, each of said channels lying wholly at one side of a diameter and the ends of said channels being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said disk element is so positioned as to have one channel in communication with one of said suction openings and the other in communication with one of said discharge openings, a stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, a second stop on one of said elements engageable by means on the other of said elements for limiting rotation of said disk element to substantially the arc between adj acent suction and discharge openings, whereby said channels may switch functions when said disk element is frictionally rotated from one position to the other depending on the direcsaid member against said disk element.

9. A reversible pump comprising a. casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavity at the other side of .said diameter, the arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internally toothed rotor gear snugly fitting one end of said cavity and freely rotatable therein, an externally toothed inner gear meshing with said rotor gear, said inner gear having a lesser number of teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side of a diameter and compression at the other, a cylindrical reversing disk element snugly filling the remainder of said cavity and having one end face frictionally engaging the exposed faces of said gears, said end face having two grooves therein, each commencing at an internal point, extending arcuately'atsuch a radius as to be adjacent some of the teeth of the gears, and then extending to the side of the disk element, each of said grooves lying wholly at one side of a diameter and the ends of said grooves being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said diskelement is so positioned as to have one groove in communication with one of said suction openings and the other in communication with one of said dischargeopenings. a stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, a second stop on one of said elements engageable'by means on the other of said elements for limiting rotation of said disk element to substantially the are between adjacent suction and discharge openings, whereby. said grooves may switch functions when said disk element is frictionally rotated from one position'to the other depending on the direction of rotation of said gears but said passageways will nevertheless function in the same manner, a .guideway in said casing extending coaxially with said cavity from the end thereof containing said disk element, a ball snugly fitting said guideway, and a spring in said guideway urging said ball against said disk element.

10. A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavity at the other side of said diameter, the arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internallytoothed rotor gear face frictionally engaging the exposed faces ofsaid gears, said disk element having two ports therein, each commencing at an internal point, extending arcuately at such a radius as to be adjacent some of the teeth of the gears, and then extending to the side of the disk element, each of said ports lying wholly at one side of a diameter and'the ends of said ports being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said disk element is so positioned as to have one port in communication with one of said suction openings and the other in communication with one of said discharge openings, a stop on one of said elements engageable bymeans on the other of said elements for holding said disk element to such position when said gears rotate in one direction, a second stop one one of said said disk element may be limited to a minimum movement by said stops. a guideway in said casing extending coaxially with said cavity from the end thereof containing said disk element, a ball in said guideway, and a spring in said guideway urging said ball against said disk element.

11. A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said snugly fitting one end of said cavity and freely rotatable therein, an externally toothed inner gear meshing with said rotor gear, said inner gear having a lesser number of teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side. of a diameter and compression at the other, a

cavity at the other side of said diameter, the arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internally toothed rotor gear snugly fitting one end of said cavity and freely rotatable therein, an externally toothed inner gear meshing with said rotor gear, said inner gear having one less teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side of a diameter and compression at the other, a cylindrical reversing disk element snugly filling the remainder of said cavity and having one end face frictionally engaging the exposed faces of said gears, said end face havingtwo grooves therein, each commencingat an internal point, extending arcuately at such a radius as to be adjacent some of the teeth of the gears, and then extending to the side of the disk element, each of said grooves lying wholly at one side of a diameter and the ends of said grooves being diametrically opposed whereby one acts-as a continuation of said suction pas-sageway and the other acts as a'continuation of said discharge passageway when said disk element is so positioned as to have one groove in communicylindrical reversing disk element snugly filling the remainder of said cayity and one end 76 merits for holding said element tosuch nor,

cation with one of said suction openings and the other in communication with one of said discharge openings, a stop on one of said elements engageable by means on the other of said elesition when said gears rotate in one direction, a second stop on one of said elements engageable by means on the other of said elements for limiting rotation of said disk to substantially the are between adjacent suction and discharge openings, whereby said grooves may switch functions when said disk element is frictionally rotated from one position to the other depending on the direction of rotation of said gears but said passageways will nevertheless function in the same manner, a pressure opening in said casing element extending coaxially with said cavity from the end thereof containing said disk element, and a connection from said discharge passageway to said pressure opening.

12. A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said I cavity at the other side of said diameter, the

arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge "openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internally toothed rotor gear snugly fitting one end of said cavity and freely rotatable therein, an externally toothed inner gear meshing with said rotor gear, said inner gear having one less teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side of a diameter and compression at the other, a cylindrical reversing disk element snugly filling the remainder of said cavity and having one end face frictionally engaging the exposed faces of said gears, said disk element having two channels therein, each commencing at an internal point, extending arcuately at such a radius as to be adjacent some of the teeth of the gears, and then extending to the side of the disk element, each of said channels lying wholly at one side of a diameter and the ends of said channels being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said disk element is 50 positioned as to have one channel in communication with one of said suction openings and the other in communication with 4 one of said discharge openings, 2, stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, a second stop on one of said elements engageable by means on the other of said elements for limiting rotation of said disk element to substantially the are between adiacent suction and discharge openings, whereby said channels may switch functions when said disk element is frictionally rotated from one position to the other depending on the direction of rotation of said gears but said passageways will nevertheless function in the same manner, the angle subtended between the centers of adjacent suction and discharge openings being less than the angle between teeth of either of said gears whereby said disk element may be limited to a minimum movement by said stops, and means to apply the fluid pressure of said discharge passageway to the other end of said disk element.

13. A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavity at the other side of said diameter, the arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internally toothed rotor gear snugly fitting one end of said cavity and freely rotatable therein, an externally toothed inner gear meshing with said rotor gear, said inner gear having one less teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side of a diameter and compression at the other, a cylindrical reversing disk element snugly filling the remainder of said cavity and having one end face frictionally engaging the exposed faces of said gears. said end face having two grooves therein, each commencing at an internal point, extending arcuately at such a radius as to be adjacent some of the teeth of the gears, and then extending to the side of the disk element, each of said grooves lying wholly at one side of a diameter and the ends of said grooves being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said disk element is so positioned as to have one groove in communication with one of said suction openings and the other in communication with one of said discharge openings, a stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, a second stop on one of said elements engageable by means on the other of said elements for limiting rotation of said disk element to substantially the are between adjacent suction and discharge openings, whereby said grooves may switch functions when said disk element is frictionally rotated from one position to the other depending on the direction of rotation of said gears but said passageways will nevertheless function in the same manner, a tubular passageway in said casing element extending coaxially with said cavity from the end thereof containing said disk element, a connection from said discharge passageway to said tubular passageway, and a springloaded ball in said tubular passageway and urged against said disk element by combined spring and discharge pressures.

14. A reversible pump comprising a casing element having a cylindrical cavity therein, a suction passageway having two suction openings communicating with said cavity at one side of a diameter thereof, a discharge passageway having two discharge openings communicating with said cavity at the other side of said diameter, the arcuate land between said suction openings being of substantially the same length as the arcuate land between said discharge openings and the arcuate lands between adjacent suction and discharge openings being substantially of equal length, a cylindrical, internally toothed rotor gear snugly fitting one end of said cavity and freely rotatable therein, an externally toothed inner gear meshingwith said rotor gear, one of said gears being driven and driving the other, said inner gear having a lesser number of teeth than said rotor gear and being eccentrically positioned whereby suction may be established at one side ot a diameter and compression at the other, a cylindrical reversing disk element snugly filling the remainder of said cavity and having one end extending to the side of the disk element, each' of said channels lying wholly at one side of a diameter and the ends of said channels being diametrically opposed whereby one acts as a continuation of said suction passageway and the other acts as a continuation of said discharge passageway when said disk element is so positioned as to have one channel in communication with one of said suction openings and the other in communication with one Of said discharge openings, a stop on one of said elements engageable by means on the other of said elements for holding said disk element to such position when said gears rotate in one direction, a second stop on one of said elements engageable by means on the other of said elements for limiting rotation of said disk element to substantially the are between adjacent suction and discharge openings, whereby said channels may switch functions when said disk element is frictionally rotated from one position to the other depending on the direction of rotation of said gears but said passageways will nevertheless function in the 18 same manner, the angle subtended between the centers of adjacent suction and discharge openings being less than the angle between teeth of either of said gears whereby said disk element may be limited to a minimum movement by said stops, a tubular passageway in said casing extending coaxially with said cavity from the end thereof containing said disk element, a connection from said discharge passageway to said tubular passageway, and a spring-loaded ball in said tubular passageway and urged against said disk element by combined spring and discharge pressures.

WILLIAM H. WENTLING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,700,818 Wilsey Feb. 5, 1929 2,148,561 Kempton et al Feb. 28, 1939 2,151,482 Neeson Mar. 21, 1939 2,185,473 Neeson Jan. 2, 1940 2,225,228 Neeson Dec. 17, 1940 2,369,841 Neeson Feb. 20, 1945 Certificate of Correction Patent N 0. 2,490,391 December 6, 1949 WILLIAM H. WENTLING It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 42, for the word friction read frictional; column 15, line 4, after disk insert element and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofioe.

Signed and sealed this 28th day of March, A. D. 1950.

THOMAS F. MURPHY,

Assistant Oommz'ssz'oner of Patents. 

